documentclass[a4paper]{article}

usepackage{linguex}

usepackage{tikz}
usepackage{tikz-dependency}
usetikzlibrary{shapes, positioning, shadows, trees}

begin{document}


ex.
begin{dependency}
begin{deptext}
*It was & the small & that the big brown dog chased & textit{t} & grey cat yesterday in the park\
end{deptext}
depedge[hide label, edge unit distance = 0.75ex]{4}{2}{label}
end{dependency}

end{document}